(CBS/AP) Sugary drinks over 16-ounces are on their way out of New York City, but the question on the mind of many is: Will it actually make a difference?

The latest move from the city that's set trends by banned smoking in bars and trans fats in foods involves sugary drinks sold at restaurants, fast-food chains, theaters, delis, office cafeterias and other places that fall under the New York City Board of Health's regulation by March 2013. Exempt will be drinks sold in convenience and grocery stores, as well as dairy and alcohol-based beverages. Restaurants with self-serve soda fountains will be prohibited from giving out cups larger than 16 ounces, even for diet drinks, but consumers will be allowed refills.

The Board of Health approved the big-soda ban 8-0, with one member, Dr. Sixto Caro, an internal medicine doctor at NYU Langone School of Medicine, abstaining because he felt the plan wasn't comprehensive enough. Barring any legal action, the sugar-sweetened drinks measure will take effect in March.

Public health experts around the nation - and the restaurant and soft-drink industry - will be watching closely to see whether the new restrictions will make a difference and lead to changes in the way New Yorkers eat and drink.

No other U.S. city has tried to tackle obesity by restricting portion sizes at restaurants, but city officials wanted to take action as a way of getting a skeptical public to embrace the idea that empty-calorie foods are a menace.

Mayor Michael Bloomberg on Thursday likened the restrictions on caloric soft drinks to banning lead paint, and cited the surge in young children being diagnosed with a type of diabetes more commonly found in overweight adults.

Many wonder whether the ban will even make a health difference given the complex factors involved in obesity.In July, Dr. Brian Elbel, an assistant professor of population health and health policy at NYU Langone School of Medicine in New York City, explained to CBSNews.com that his research found if 100 percent of fast food consumers switched to a 16-ounce drink, a consumer on average would take in 63 fewer calories every time they set foot in the restaurant - assuming they don't get a refill.

Elbel told CBSNews.com following the ban's approval that he still thinks there's potential for this policy to influence fast food beverage consumption. However he also concedes the ban alone will not solve the obesity epidemic, given many people over-consume by 250 calories or more per sitting.

"It's a very nice first step," he said. "We're going to nudge you in the direction of hopefully purchasing fewer ounces of [sugar-sweetened drinks]."

But will New Yorkers listen, or simply turn to the thousands of stores and not covered under the measure?

By nature, many may see the restrictions as an infringement on personal liberty. A New York Times poll last month showed that six in 10 New Yorkers opposed the rule.

Complying may also prove complicated for some establishments with food-service licenses.

Starbucks is trying to figure out whether it will be barred from selling Frappuccinos in the 24-ounce size. The sugary drink comes packed with calories, but is also made with a significant amount of milk and the new rule would exempt products made of at least 50 percent milk. Iced coffee, which many cafes sweeten with liquefied sugar, may too be an issue.

"We're looking at all of our beverages internally," said Starbucks spokeswoman Linda Mills. "I think there will be a lot of subtleties to work out."

The restaurant and beverage industries complained that the city is exaggerating the role sugary beverages have played in making Americans fat compared to other snacks and desserts.

"Proposals like the soda ban discourage new business and hurt our reputation as the dining capital of the world," Andrew Moesel, spokesperson for the New York State Restaurant Association, said in a statement. "Reducing obesity is an important goal, but we want to partner with government to come up with effective ways to confront the problem. What we don't need is more burdensome regulation making it harder for businesses to function."

Eliot Hoff, a spokesman for an industry sponsored group called New Yorkers for Beverage Choices, claims to have gathered more than 250,000 signatures on petitions against the plan. He said the group is considering suing to block the rule, but no immediate legal action was announced.

Asked whether he was concerned about "well-funded" opposition from an industry with deep pockets, Bloomberg, a billionaire emerging as a major philanthropist on public health issues, suggested he wouldn't be outgunned.

"I don't know it's well-funded. I've just spent roughly $650 million of my own money to try to stop the scourge of tobacco, and I'm looking for another cause. How much were they spending, again?" he said.

What's more, a legal challenge may be an uphill battle.

In June, the CBS Evening News reported on some possible legal challenges the ban may face.

"We're going to look at all of our options to protect our business, our rights to do business and our rights not to be discriminated against," Steve Cahillane, a senior executive with Coca-Cola, told CBS News at the time. "We won't take anything off the table."

Bennett Gershman, a constitutional law professor at Pace University, argued at the time that the ban may violate the Constitution's Commerce Clause.

Local governments "can't pass laws that do impose burdens on the free flow of commerce between states," he said.

However, food law expert Diana R. H. Winters, an associate professor at the Indiana University Robert H. McKinney School of Law, told CBSNews.com after the ruling that the ban would likely withstand a legal challenge.

She said any arguments about restricting commerce would likely fail because the regulation would have to withstand what's called a "rational basis of scrutiny," meaning the city would have to prove a connection between sugar-sweetened drinks and public health - not exactly a stretch given existing research.

"They probably don't have a leg to stand on," Winters said of the associations exploring legal action.

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